Swiveling caster assemblies are well known and widely used. Some such caster assemblies have devices to lock the caster wheel, when desired, to prevent inadvertent rolling movement after the supported object has been parked in a desired location. Some of them also have devices to disable the swivel feature to prevent swiveling of the caster relative to the object when the object is parked. Some have a combination of swivel lock and wheel lock features.
Swiveling casters are also provided with various arrangements for mounting to the object to be supported. One type of mount that is widely used is a plate having holes through it to receive fasteners for attaching it to the bottom of the object to be supported. A bearing structure is provided between the plate and the caster horn. Another type of mount is a stem fastened to the caster horn and projecting upward from the caster horn and received in a downwardly opening socket in the object supported. One version of this approach has a resilient metal split ring received in a groove in the stem and engaging a wall of the socket and frictionally retaining the stem in the socket. But there is sufficient space between the ring and the groove for the stem to rotate in the socket and enable the stem, and thereby the caster, to swivel in the socket. Another type of mount is a threaded stem which is screwed into a socket in the object to be supported and which has features at the lower end for reception in a socket in the caster horn or for mounting through a ball bearing assembly to the caster horn.
In addition to the above-mentioned possibilities for various combinations of features, aesthetic considerations have increasing importance for some markets. Color variety and avoidance of appearance-compromising rust and tarnish have led to adoption of plastics in some instances. Customers can require certain colors.
It occurs to us that, because of the wide variety of features and combinations of features that customers of caster manufacturers might want, it would be desirable to have a basic caster assembly which is easily adapted to various customer requirements. The present invention is addressed to assisting a caster manufacturer to successfully address one or more of the aforementioned possible customer desires.
Described briefly, according to a typical embodiment of the present invention, a caster assembly is provided with a caster horn with an upwardly opening special receiver therein configured to receive a special stem configured according to the invention for mounting to various types of objects to be supported by such casters. Various mounting devices are provided, all of them with the special stem for reception in the special receiver. One embodiment of mounting device is a plate having the special stem embedded in it and projecting downward from it. Another embodiment is an upward projection from the special stem and which has a groove with a split ring for snap-in connection into a socket in the object to be supported. Another embodiment is an upward projection of the special stem and which is threaded to be screwed into a socket in an object to be supported. The special stem and receiver have a cooperating snap-in feature whereby the stem is retained in the receiver of the horn, once installed with the horn.
The horn according to the invention has a slot for reception of either a snap-in cover if there is to be no lock assembly, or for installation of a brake operating lever if the caster assembly is to have a wheel lock, a swivel lock, or a combination of wheel and swivel lock. The caster horn and either the cover or the brake operating lever, as the case may be, are made of molded plastic.